Did you know, by default, the Samsung Health app and your watch sync constantly for counting steps? You can significantly improve battery life by turning this function off. Go into the Samsung Health app, tap on steps, then tap on the three dots in the upper right hand corner and tap on Frequent Syncing. Turn that off. Since I did this 4 days ago I am seeing about a 33% increase in my battery life. Typically I was getting about a day and a half, now I'm getting over 2 days on my Galaxy Watch6 Classic.
Well, the hack saves a lot of power, but you can save more if you want. If the hack suits your purpose - enjoy. I prefer low power mode, my preference, as there are more apps consuming power other than the just the step synch.
